Ok. I'm on Vocaloid 3 and I always just export the voice and mix everything in Reason (my DAW of choice). I don't have much experience using the EQ or Compressor in Vocaloid 3, but that shouldn't matter too much.
Hmm...let me see if I can find the original track on youtube. Is this it -
Here?
I just listened to your youtube video again, and compared it to the original.
Unless I'm going crazy, the instrumentals are different. It's like it has been mixed again, with more stereo width in the drums. Your instrumental definitely is of better quality.
Ok, it's going to be somewhat difficult to walk you through, but hopefully I can get you closer. The first thing that sticks out to me is there is more presence (2k-4k) in the vocals on the original compared to yours. Try using a somewhat broad eq boost (lets try 3dbs worth) centered about 2.5k on your vocals. You will now notice that you can lower the overall level of the vocal track in relation to the instrumental, while still being audible. Its going to be a delicate balancing act: eq boost compared to overall level.
Now, you can choose to compress after, or before the EQ. I would suggest compressing before for now. Then add the presence boost after. You can always eq first, compress second, then eq after again, if the compressor flattens your EQ changes too much. But maybe lets keep it simple for now.
There's so much information to talk about on this subject and I don't want to overwhelm you.
Just to summarize my suggestions:
1. Compressor
2. Somewhat broad eq boost (lets try 3dbs worth) centered about 2.5k on your vocals
3. Lower level of vocal if necessary.
I hope this advice helps you in any way. Feel free to play around with that. My ears aren't too sharp right now (I'm really out of mixing practice).